1. Field of the Invention
This invention relates to physical therapy devices and particularly to physical therapy devices used for correcting gait and balance problems caused by neurological dysfunction.
2. Prior Art
Following neurological damage caused by a cerebrovascular accident (CVA), traumatic brain injury (TBI), cerebral palsy (CP), multiple sclerosis (MS) and others, persons will often experience neuromotor difficulties as well as visual dysfunctions which interfere with posture, balance and gait. These visual dysfunctions then have a significant detrimental effect upon the ambulation or mobility of the person.
Studies have determined that visual midline shift syndrome (VMSS) as a visual syndrome will affect balance, posture and ambulation. Persons with visual midline shift syndrome will shift their concept of the visual midline of their body away from the center causing them to lean, in most cases, in the direction of the midline shift. This can cause a tendency to lean or drift when walking to the right or the left. In addition, anterior and posterior shift of the axis may cause the individual to lean forward or backward. Visual midline shift syndrome not only affects ambulation but also posture while seated.
It has also been determined that individuals which have experienced neurological damage which interfered with their posture, balance and gait will further restrict counter-torsional movements of their upper body when attempting to walk. The purpose of the counter-torsional movement is to assist with balance. For example, in normal walking patterns when a foot and a leg is extended, the person rotates the upper body and the upper side forward. In other words, a step with the left foot will produce a rotation of the right shoulder and a swing of the right arm forward in order to counter-balance the movements of the lower body. In normal walking/gait patterns, this produces a swinging motion of the arms due to the counter-rotation of the upper body. Often in conjunction with a visual midline shift syndrome and/or other neurological problems, individuals will restrict the movement of the upper body or develop a pathological gait pattern, causing the shoulder and arm of the same side of the body as the foot that is extended to be rotated forward. This causes these individuals to have difficulties with balance, coordination, gait and ambulation.
The treatment for visual midline shift syndrome (VMSS) typically includes the use of yoked prisms to shift the midline back to the center. However, while the yoked prisms may shift the midline back to the center, in most cases the persons still retain a restricted and undifferentiated upper body movement and/or what is known as homolateral movement. This residual homolateral movement causes the shoulder and arm of the same side to be rotated forward in relation to the foot and leg on the same side and still causes some difficulties with balance, coordination, gait and ambulation.